Leonaed f



, UNITED STATES,

PATENT OFFICE.

LEONARD F. DUNN, OF ONEIDA COMMUNITY, NEW YORK.

PROCESS OF NICKEL-PLATING.

SPECIFICATION forming part of Letters Patent No. 289,337, dated November27, 1883.

Application filed September 13, 1883, (No specimens.)

To all whom it may concern:

Be it known that I, LEONARD F. DUNN, of Oneida Community, in the countyof Madison, in the State of New York, have invented new and usefulImprovements in Process of N ickel- Plating, of which the following is afull, clear,

and exact description.

In the art of nickel-plating articles of inferior metal it has beenfound that, although said sorted to the method of enveloping thenickelplating between two coats of silver, as set forth in my Patent No.278,784, dated June 5, 1883. Although this method accomplished toa greatextent the desired object, it, however, proved somewhat expensive.

Having in my experiments discovered that by combining with thenickel-plating a plating of silver or copper or other ductile or malleable metal, the latter becomes more or less amalgamated with the nickel,and imparts thereto sufficient tensile strength to enable it to resistthe strains incident to ordinary contor ton of the article to which itis applied. I. nowapply the nickel-plating by interposing between twocoats of said plating a plating of silver or copper or other ductile ormalleable metal. The first coat of nickel may be either applied directto the article to be plated or to a coatof other metal previouslyapplied to said article. The plating of silver or copper or otherductile metal is next applied to the first coat of nickel, and thenanother coat of the latter is made to cover the ductile metal. coats ofnickel and of ductile metal can be continued to produce a plating ofalmost any desired thickness, said coating being applied by the ordinaryelectroplating process; and

in practice I prefer to transfer thearticle under treatment from onebath to another as quickly as practicable, so as to expose the metalsurfaces as little as possible to the atmosphere, and prevent thesolution of one bath from becoming dry on the article before plating ofthe This process of alternating the the application thereto of the nextsolution. The ductile metal coating, which is thus interposed betweenthe two nickel-platings, becomes to a great extent amalgamatedtherewith, and while forming a thorough tie of the several layers it atthe same time imparts to the nickel-plating a degree of ductility whichenables it to withstand considerable tensile strain.

I am aware that prior to my invention various methods have been resortedto to apply platings of precious metalto articles of inferior metal. Inone instance a nickel coating has been applied directly to the inferiormetal to form the base for a finishing coat of silver; in another case asilver coating has been first applied to the inferior metal, and afterhighly bu rnishing said silver coating a nickel-plating was appliedthereto; and, again, in another case a film of tin has been combinedwith the nickel-plating electrically deposited; but it will be observedthat neitherof said prior methods produced a plating possessing thedurability of the multiple coats of nickel united by, and to some extentamalgamatec'l with, interposed thin coats of silver, as hereinspecified. Therefore What I claim as new, and desire to secure byLetters Patent, is-

l. The method of nickel-plating inferior metal by inter-posing betweentwo coats of nickel a coat of silver or other ductile metal, said coatsbeing successively applied byordinary electroplating process,substantially as set forth.

2. The process of nickel-plating inferior metal, consisting in applyingby means of electrolysis alternate coats of nickle and coats of ductilemetal, ending with a coat of nickel, and in applying the successivecoats, transfer ring the article under treatment from one bath to theother without exposing the metal surfaces to the action of theatmosphere, substan tially as set forth.

In testimony whereof I have hereunto signed my name and affixed my seal,in the presence of two attesting witnesses, at Syracuse, in the countyof Onondaga, in the State of New York, this 3d day of September, 1883.

LEONARD F. DUNN. [L. s.] WVitnesses:

FREDERICK H. GIBBs, WM. 0. RAYMOND.

